The Prime Minister will vow to “give everything” to deliver the Good Friday Agreement’s vision of a united society in Northern Ireland.

Rishi Sunak is due to address a conference in Belfast as part of commemorations marking the 25th anniversary of the signing of the Belfast (Good Friday) Agreement (BGFA).

During a speech set to be given on Wednesday, the Conservative Party leader is expected to say that he will “use the full force of the UK Government to help” grow Northern Ireland’s economy and “fulfil the true promise” of the peace pact.

The 1998 deal, signed by former prime minister Sir Tony Blair and former taoiseach Bertie Ahern and partly brokered by the US, helped stem the sectarian bloodshed of the Troubles that had blighted Northern Ireland for decades.

Following concessions made on both sides during the negotiations, the Good Friday Agreement created powersharing institutions at Stormont that involved nationalists and unionists governing Northern Ireland together in a mandatory coalition arrangement.

While the pact largely ended the Troubles, which had claimed more than 3,600 lives since the late 1960s, it has failed to bring long-term political stability in the region and devolution has collapsed several times in the last two decades.

The anniversary comes amid another period of collapse, with the DUP blocking powersharing in protest at post-Brexit trading arrangements that have created economic barriers between Northern Ireland and Great Britain.

Mr Sunak’s Windsor Agreement, revealed earlier in the year, contains a series of reforms which the Prime Minister hopes will ease trade frictions and also encourage the DUP to form a new government in Belfast with Sinn Fein.

He will travel to the city after Prime Minister’s Questions to address Queen’s University’s Agreement 25 conference and host a Gala Dinner to commemorate the anniversary.

Former prime minister Sir Tony Blair and former taoiseach Bertie Ahern were leaders at the time of the Good Friday Agreement (Liam McBurney/PA)

The Prime Minister is expected to say: “Together we must fulfil the true promise of the 1998 agreement.

“That future enshrined in the very words of the text – of ‘sustained economic growth’, and where we tackle the problems of ‘a divided society’.

“And I will give everything to help deliver that vision.

“BGFA promised prosperity and a more integrated society and we have work to do to deliver on that promise.”

During his dinner speech, which former prime ministers Boris Johnson and Liz Truss are expected to attend, Mr Sunak will also herald those who helped bring about the agreement a quarter of a century ago.

“Courage, imagination, and perseverance — those qualities brought an imperfect but enduring peace to a place taught to believe no such peace was possible,” Mr Sunak will say.

“To all those who led us to that peace, including those here in this hall and those no longer with us – let us take this moment to say to you: thank you.”

Rishi Sunak met US President Joe Biden during his visit to Northern Ireland

Having negotiated the Windsor Agreement with the European Union, Downing Street said Mr Sunak will address his economic ambitions for Northern Ireland.

Officials said the British leader is keen to deliver a “prosperous economy and a more united and contented society” for the province, with plans in his speech to touch upon attracting greater investment and building upon the cyber, life sciences, financial services and creative industries.

In extracts of the speech briefed beforehand, Mr Sunak said: “I know that journey to prosperity won’t be easy – and we aren’t there yet.

“But this is my commitment to you: I will use the full force of the UK Government to help you make this one of the best places in the world to start and grow a business, create jobs, train and learn new skills, and attract investment.”

The event will round off the recent period of Prime Minister-led events to mark the anniversary of the 1998 agreement.

Having met US President Joe Biden in Northern Ireland last week, Mr Sunak will speak with architects of the Good Friday Agreement at the Gala Dinner, along with Irish and US representatives.

The dinner will be attended by political leaders, international dignitaries and leading charities, No 10 said.